Very Old Trick.

Star (Christchurch), Volume LXVI, Issue 20544, 20 February 1935, Page 6

Very Old Trick.

Nature Notes.

By

James Drummond. F.L.S.. F.Z.S.

'JHIE PILL WOODLOUSE’S trick of rolling itself into a ball when danger threatens is as old as the hills. Geologists will say that it is older than hills and mountains we see, some of which are in their geological youth. The earliest crustaceans known, called trilobites, which wore shields or bucklers on their heads, rolled themselves into little balls when danger was near, in the same way as pill woodlice do at present. Those ancient crustaceans lived in the sea, not on land, keeping mainly to the muddy bottom, on which they crawled.* They were plentiful in New Zealand’s Palaeozoic seas. They developed to an extraordinary degree in kinds and individuals, until seafloors in parts of the world were thick with them. Some species were no longer than pill w’oodlice, about a quarter of an inch. Others were three inches long. There were giants twenty inches long. Trilobites’ remains in in the earliest fossil-bearing rocks testify tc their remote history. When their records began, they had travelled a long way on the rough road. Their origin is unknown. What is certain is that their armour—perhaps also their little box of tricks—stood them in good stead for ages. Their enemies increased in numbers, size and cunning. Trilobites then became less plentiful. Having started downhill they went the pace rapidly. They were completely blotted out. They were more primitive than any other crustaceans known of, but their remarkable rise, decline, degeneration, fall and extirpation made them the most interesting of all crustaceans.